Demetalation of hydrocarbon charge stocks

ABSTRACT

This specification discloses the demetalation of a hydrocarbon charge stock. The demetalation procedure involves contacting the hydrocarbon charge stock with hydrogen in the presence of, as a catalyst, a material derived from the naturally-occurring underwater deposit known as a manganese nodule. The manganese nodule may be employed without pretreatment or may be pretreated by sulfiding or by leaching to remove and recover one or more valuable metallic constituents. The manganese nodule catalyst, after it has become deactivated by use, may be processed to remove and recover one or more valuable metallic constituents.

United States Patent Weisz et al.

[54] DEMETALATION OF HYDROCARBON CHARGE STOCKS [75] Inventors: Paul B.Weisz, Yardley; Anthony J.

Silvestri, Morrisville, both of Pa.

[73] Assignee: Mobil Oil Corporation [22] Filed: Dec. 23, 1970 [21]App1.No.: 100,931

[52] US. Cl ..208/211, 208/251 H, 252/454 [51] Int. Cl. ..Cl0g 23/02[58] Field of Search ..208/251, 253, 211, 208, 209, 208/213, 249, 295,298, 299, 210, 110; 252/471, 454; 75/115 [56] References Cited UNITEDSTATES PATENTS 3,214,236 11/1965 Weisz ..252/471 3,471,285 11/1969 Rolf3,509,041 4/1970 Miale ..208/119 HYDROGEN MAKE-UP HYDROGEN GAS PURGE 24RECYCLE 2! 23 22 FINES SEPARATOR DEMETAL- ATION :0, REACTOR MN 25 12\ :2

V U FINES I4 FRESH R J-' CATALYST HYDROCARBON FEED ' H FURNACE SPENTCATALYST Primary ExaminerPaul M. Coughlan, Jr.

Assistant ExaminerG. J. Crasanakis Attorney-Frederick E. Dumoulin,William J. Scherback, Oswald G. Hayes and Andrew L. Gaboriault [57]ABSTRACT This specification discloses the clemetalation of a hydrocarboncharge stock. The demetalation procedure involves contacting thehydrocarbon charge stock with hydrogen in the presence of, as acatalyst, a material derived from the naturally-occurring underwaterdeposit known as a manganese nodule. The manganese nodule may beemployed without pretreatment or may be pretreated by sulfiding or byleaching to remove and recover one or more valuable metallicconstituents. The manganese nodule catalyst, after it has becomedeactivated by use, may be processed to remove and recover one or morevaluable metallic constituents.

23 Claims, 4 Drawing Figures PRODUCT PATENTEI] FEB 1 31973 SHEET 2 BF 4PATENTEU 31915 $716,479

SHEET NF 4 FIG. 4

LIGHT GASES To 400F 54 ATMOSPHERIC CHARGE 400F 600F STOCK DISTILLATIONCATALYTIC 600F+ DEMETALATION CRACKING REACTOR UNIT if! 55 6O VACUUMDISTILLATION TO THERMAL PROCESSING PAUL B. WEISZ ANTHONY J. SILVESTRIINVENTORS BYW $M ATTORNEY DEMETALATION OF HYDROCARBON CHARGE STOCKSBACKGROUND OF THE INVENTION I l. Field of the Invention This inventionrelates to the treatment of a hydrocarbon charge stock and relates moreparticularly to the treatment of a hydrocarbon charge stock to effectremoval therefrom of organo-metallic compounds.

2. Description of the Prior Art U.S. Pat. No. 3,214,236 discloseshydrogenation, desulfurization and denitrogenation as being conversionprocesses in which manganese nodules are catalytically useful. Thispatent also discloses that the manganese nodule catalyst can be a sourceof manganese and other valuable metals after being spent in effectingthe desired catalytic conversion.

U.S. Pat. No. 3,509,041 discloses the use of manganese nodules, afterpretreatment by base exchange to bond hydrogen ions thereto, inhydrocarbon conversion reactions, specifically cracking, hydrocracking,oxidation, olefin hydrogenation, and olefin isomerization.

U.S. Pat. No. 3,330,096 discloses the use of manganese nodules forremoving sulfur compounds from gases.

U.S. Pat. No. 3,471,285 discloses the selective separation of manganeseand iron from manganese nodules which also contain cobalt and nickel byreducing the nodules at elevated temperatures and then leaching with anaqueous solution of ammonium sulfate.

SUMMARY OF THE INVENTION In accordance with the invention, a hydrocarboncharge stock is demetalized by contacting the charge stock withhydrogen, in the presence of, as a catalyst, a material derived from thenaturally-occurring underwater deposit known as a manganese nodule. Inaccordance with a specific embodiment of the invention, the manganesenodule is employed without pretreatment. In accordance with otherspecific embodiments of the invention, the manganese nodule may bepretreated by sulfiding, or by leaching to remove one or more metallicconstituents, or by any combination of the pretreating procedures. Inaccordance with still another embodiment of the invention, the catalyst,after becoming deactivated by use, is treated to remove and recovertherefrom one or more metallic constituents.

BRIEF DESCRIPTION OF THE DRAWINGS FIGS. 1 and 2 of the accompanyingdrawings are photomicrographs of the surfaces of the manganese nodules.

FIG. 3 is a flow diagram illustrating a procedure wherein demetalationof a hydrocarbon charge stock is carried out and the charge stock isthen processed for sulfur and/or nitrogen removal.

FIG. 4 is a flow diagram illustrating a procedure wherein demetalationof a hydrocarbon charge stock is carried out and the charge stock isthen subjected to catalytic cracking.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Various hydrocarbon chargestocks such as crude petroleum oils, topped crudes, heavy vacuum gasoils, shale oils, oils from tar sands, and other heavy hydrocarbonfractions such as residual fractions and distillates contain varyingamounts of non-metallic and metallic impurities. The non-metallicimpurities include nitrogen, sulfur, and oxygen and these exist in theform of various compounds and are often in relatively large quantities.The most common metallic impurities include iron, nickel, and vanadium.However, other metallic impurities including copper, zinc, and sodiumare often found in various hydrocarbon charge stocks and in widelyvarying amounts. The metallic impurities may occur in several differentforms as metal oxides or sulfides which are easily removed by singleprocessing techniques such as by filtration or by water washing.However, the metal contaminants also occur in the form of relativelythermally stable organo-metallic complexes such as metal porphyrins andderivatives thereof along with complexes which are not completelyidentifiable and which are not so readily removed.

The presence of the metallic impurities in the hydrocarbon charge stocksis a source of difficulty in the processing of the charge stocks. Theprocessing of the charge stock, whether the process is desulfurizing,cracking, reforming, isomerizing, or otherwise, is usually carried outin the presence of a catalyst and the metallic impurities tend to fouland inactivate the catalyst to an extent that may not be reversible.Fouling and inactivation of the catalyst are particularly undesirablewhere the catalyst is relatively expensive, as, for example, where theactive component of the catalyst is platinum. Regardless of the cost ofthe catalyst, fouling and inactivation add to the cost of the processingof the charge stock and therefore are desirably minimized.

Demetalation of the hydrocarbon charge stock can be effected by thermalprocessing of the charge stock. However, thermal processing results inconversion of an appreciable portion of the charge stock to coke and theportion of the charge stock converted to coke represents a loss ofcharge stock that desirably should be converted to a more economicallyvaluable product or products. Moreover, by thermal processing, themetallic impurities tend to deposit in the coke with the result that thecoke is less economically desirable than it would be in the absence ofthe metals.

Demetalation can also be effected by catalytic hydroprocessing of thecharge stock. However, catalytic hydroprocessing results in the catalystbecoming fouled and inactivated by deposition of the metals on thecatalyst. There is no convenient way of regenerating the catalyst and itultimately must be discarded. Since these catalysts are relativelyexpensive, catalytic hydroprocessing to demetalize hydrocarbon chargestocks has suffered from adverse economics.

By the process of the invention, an economical and effectivedemetalation of a hydrocarbon charge stock is obtained. Manganesenodules are readily available in large quantities and are relativelyinexpensive. Further, material derived from the nodules is capable ofeffectively removing the metallic impurities from a hydrocarbon chargestock. Thus, whereas the material obtained from the manganese nodulesbecomes fouled and inactivated by the demetalizing process, the materialis obtainable at such low cost that the fouled and inactivated materialcan be discarded without significant effect on the economics of thedemetalizing process.

Manganese nodules, as is known, are naturally occurring deposits ofmanganese, along with other metals, including iron, cobalt, nickel, andcopper, found on the floor of bodies of water. They are found inabundance on the floors of oceans and lakes. For example, they are foundin abundance on the floor of the Atlantic and Pacific Oceans and on thefloor of Lake Michigan. The nodules are characterized by a large surfacearea, i.e., in excess of 150 square meters per gram. The nodules have awide variety of shapes but most often those from the oceans look likepotatoes. Those from the floor of bodies of fresh water, such as thefloor of Lake Michigan, tend to be smaller in size. Their color variesfrom earthy black to brown depending upon their relative manganese andiron content. The nodules are porous and light, having an averagespecific gravity of about 2.4. Generally, they range from one-eighthinch to 9 inches in diameter but may extend up to considerably largersizes approximating 4 feet in length and 3 feet in diameter and weighingas much as 1,700 pounds. In addition to the metals mentioned above, themodules contain silicon, aluminum, calcium and magnesium, and smallamounts of molybdenum, zinc, lead, vanadium, and rare earth metals.

The chemical and physical properties of manganese nodules, as catalyticagents for the demetalation of hydrocarbon charge stocks, are, ascompared with conventional catalytic agents for this purpose, consideredto be somewhat unusual. The nodules have a high surface area, aboutl-250 square meters per gram. They will, however, lose surface area bymetal deposition during the demetalation reaction. Further, as shown byRoger G. Burns and D. W. Fuerstenau in American Mineralogist, Vol. 51,1966, pages 895-902, Electron-Probe Determination of Inter-ElementRelationships in Manganese Nodules, the concentrations of the variousmetals contained in the nodules, i.e., the manganese, iron, cobalt,copper, and nickel, are not uniform throughout the crystalline structureof the nodule. Rather, a traverse across a section of a nodule will showmarked differences in the concentrations of the various metals frompoint to point of the traverse. However, there appears to be acorrelation between the concentrations of iron and cobalt. 0n the otherhand, manufactured catalysts for demetalation are usually as uniform asthe manufacturer can achieve.

The accompanying figures illustrate the structure of manganese nodules.These nodules were obtained from the Blake Plateau in the AtlanticOcean. Each of FIGS. 1 and 2 is a photomicrograph of a surface of thenodules, FIG. 1 showing more of the pore system than FIG. 2.Magnifications in each figure are l5OX.ln each of the figures, the largedark areas are large pores. The lightand dark-banded regions are solidmaterial. The nodules are formed by slow deposition of colloidalmaterials. The composition of the particles of the colloidal materialsvaries with time resulting in the microscopic stratification andinhomogeneity shown in the figures.

The manganese nodules can be employed as the catalyst for thedemetalation of the hydrocarbon charge stock substantially as mined, orrecovered, from the floor of the'body of water in which they occurred.Thus, the nodules, as mined, possibly after washing to remove sea wateror lake water therefrom and mud or other loose material from the surfaceof the nodules, may be employed for demetalation.

The demetalation reaction may also be carried out employing, as thecatalyst, manganese nodules which have been subjected to a pretreatment.Pretreatments to which the manganese nodules may be subjected includesulfiding or leaching to remove therefrom one or more components of thenodules.

Sulfiding of the manganese nodules increases the extent of demetalizingof the charge stock. It also can increase the extent of desulfurizationand Conradson Carbon Residue (CCR) reduction, each of which isdesirable. This treatment is carriedout by contacting the nodules withhydrogen sulfide. The hydrogen sulfide may be pure or may be mixed withother gases. However, the hydrogen sulfide should be substantially freeof hydrogen. The temperature of sulfiding may be from about 300 F. toabout 450 F. and the time of sulfiding may be from about 4 to about 8hours. The sulfiding may be effected, for example, by passing thehydrogen sulfide over the manganese nodules continuously during thesulfiding reaction. The space velocity of the hydrogen sulfide is notcritical and any space velocity compatible with the equipment and suchthat some hydrogen sulfide is continuously detected in the exit streamis suitable.

The manganese nodules may also be pretreated by being subjected toleaching to remove therefrom one or more components. As mentionedpreviously, the manganese nodules contain, in addition to manganese,copper, nickel, and molybdenum. They may be pretreated to leachtherefrom the copper, nickel, or molybdenum,or any two, or all three, ofthese metals. The manganese nodules contain the copper, nickel, andmolybdenum in sufficient quantities to provide a commercial source ofthese metals. Further, the removal, at least partially, of these metalsand other of the metallic constituents of the nodules has apparently noeffect on the catalytic activity of the nodules for demetalation ofhydrocarbon charge stocks. Thus, by this embodiment of the invention,copper, nickel, and molybdenum, and other metals, may be recovered fromthe nodules for the economic advantage to be gained by such recovery andthe remainder of the manganese nodules can then be employed as acatalyst for demetalation of hydrocarbon charge stocks.

Removal of the copper and the nickel may be effected by leaching themanganese nodules with an aqueous solution of a strong acid. By strongacid is meant such acids as hydrochloric, sulfuric, and nitric acids.

The molybdenum may be removed from the manganese nodules by leachingthem with aqueous base solutions such as aqueous solutions of sodiumhydroxide or sodium carbonate. These solutions should have a pH of atleast 8 and preferably should have a pH of at least 10. The leachingwith the aqueous base solutions can be carried out at ambienttemperatures or at the boiling point of the solution.

The nodules, with or without pretreatment, may be crushed and sized toobtain a desired particle size depending upon the type of demetalationoperation employed, for example, a fixed bed operation, an ebullitionoperation or otherwise.

The demetalation reaction is carried out by contacting the hydrocarboncharge stock simultaneously with the catalyst and with hydrogen. Thetemperatures at which the reaction is carried out can be from about 650F. to about 850 F. At the higher temperatures, a greater degree ofdemetalation occurs. However, the temperatures employed should not be sohigh as to effect an undesirable degree of alteration of the chargestock. Preferably, the temperatures employed are in the range of 750-850F. The pressures at which the reaction is carried out can be from about100 to about 3,000 pounds per square inch gage (psig). Preferably, thepressures employed are in the range of 500-2,000 psig. Where thereaction is carried out by passing the hydrocarbon charge stock througha bed of the catalyst, the liquid hourly space velocity (LHSV) of thecharge stock can be from about 0.2 to 4, preferably 0.5 to 2, volumes ofcharge stock per volume of catalyst per hour. Hydrogen circulation is atrates of 2,000-1S,000, preferably 5,000l0,000, standard cubic feet ofhydrogen per barrel of hydrocarbon charge stock. The hydrocarbon chargestock along with the hydrogen may be passed upwardly through a fixed bedof the catalyst in an upflow reactor or may be passed downwardly througha fixed bed of the catalyst in a downflow trickle-bed reactor. Thereaction may also be carried out by passing the charge stock and thehydrogen through an ebullient bed of the catalyst. The reaction may alsobe carried out by contacting the charge stock, the hydrogen, and thecatalyst in a batch reactor.

The catalyst, after being employed in the demetalation reaction andhaving become catalytically deactivated, or spent, can be treated forthe recovery therefrom of valuable metals. Thus, the catalyst, afterbecoming spent, may be treated to recover copper, nickel, molybdenum, orany two, or all three, of these metals. It may also be treated torecover therefrom any other component.

An advantage of the process of the invention resides in its economy withrespect to hydrogen consumption. During the demetalation reaction,hydrogen is consumed and the consumption of the hydrogen adds to thecost of demetalation. Thus, reduction in the consumption of the hydrogenis economically desirable. Prior processes directed to demetalation haveoften required consumption of hydrogen in amounts between about 450 and1,000 cubic feet per barrel of hydrocarbon charge stock. As compared tothis, by the process of the invention, effective demetalation can beeffected in many instances with consumption of 50 to 300 cubic feet ofhydrogen per barrel of hydrocarbon charge stock.

While we do not wish to be limited to the consequences of any theory, itis believed that the reduced hydrogen consumption to a large extent isdue to the sensitivity of the manganese nodules to the effects ofsulfur. Manganese nodules, as well as other catalysts heretoforeemployed for the demetalation of hydrocarbon charge stocks, effecthydrogenation of molecules other than those containing metals. Thus, themanganese nodules, as well as other demetalation catalysts, will effecthydrogenation of benzene rings, for example. This hydrogenation ofmolecules other than those containing metals therefore results inconsumption of the hydrogen in addition to that related to demetalationand, from the standpoint of the desired demetalation, represents a wasteof hydrogen. However, as contrasted with other demetalation catalysts,the manganese nodules, in the presence of sulfur, have essentially noactivity for hydrogenating benzene and other aromatic molecules. Theywill, however, hydrogenate olefins. Hydrocarbon charge stocks containsulfur to a greater or lesser extent, and, regardless of whether thecatalyst is subjected to a sulfiding pretreatment, the sulfur in thehydrocarbon charge stocks will effect a rapid sulfiding of the nodules.As a result, hydrogenation of the aromatic constituents of the chargestock is reduced with resulting reduction in the consumption of thehydrogen.

Whereas a rapid sulfiding of the nodules will occur from the sulfur inthe hydrocarbon charge stocks, sulfiding pretreatment of the nodules, aspreviously described, is of value. It is believed that, under reducingconditions, a reduction of the metal oxides in the nodules can occurwith consequent loss in surface area and diminished activity. Thesulfides on the other hand are more stable to reduction. Thus, when thenodules are exposed to a reducing environment either before or duringsulfiding as occurs when the sulfiding results from the sulfur in thecharge stock, a prereduction or competitive reduction of the oxides cantake place.

The process of the invention may be employed for the demetalation of anyhydrocarbon charge stock containing organo-metallic compounds.Ordinarily, these will be hydrocarbon charge stocks containingsufficient metal to cause difficulty in the processing, or othersubsequent use, of the charge stocks. Other subsequent use of the chargestocks can include burning of the charge stock as fuel wherein themetals cause corrosion problems. These charge stocks include whole crudepetroleum oils, topped crude oils, residual oils, distillate fractions,heavy vacuum gas oils, shale oils, oils from tar sands, and other heavyhydrocarbon oils. Charge stocks derived from Mid-Continent and EastTexas crudes contain small amounts of metals. For example, some EastTexas crudes contain about 0.1 part per million of vanadium and 2-4,parts per million of nickel. Charge stocks derived from West Texascrudes and foreign crudes, however, can contain larger amounts of metal.Kuwait crude can contain over 32 parts per million of .vanadium and over9 parts per million of nickel while Venezuelan crudes cancontain 200-400parts per million of vanadium and 17 to 59 parts per million of nickel.

The process of the invention can be carried out in conjunction withsubsequent steps of processing of the hydrocarbon charge stock. Forexample, the hydrocarbon charge stock can be subsequently processed forremoval of sulfur and/or nitrogen. Further, for example, the hydrocarboncharge stock can be subsequently processed by catalytic cracking.

Concerning processing of the hydrocarbon charge stock for removal ofsulfur and/or nitrogen subsequent to demetalation employing manganesenodules, this catalyst in the subsequent step. For sulfur and/ornitrogen removal, relatively expensive manufactured catalyst,particularly suited for this purpose, is employed. The prior removal ofa significant fraction of the metals by the manganese nodules willreduce the deterioration of the more expensive manufactured catalyst bypoisoning from the metals in the charge stock and lead to extended lifeof the more expensive catalyst. The processing sequence is unique inthat the overall results are not mere additive results of the steps;catalyst life of the desulfurization catalyst is modified by thepresence of the nodules, while the nodules perform a dual function ofboth demetalation and partial desulfurization.

The desulfurization catalyst suitable for use in such a combinationprocess is broadly characterised as any hydrogenation catalyst which istolerant of sulfur and nitrogen and which can be employed in anoperating cycle or onstream life that is economically attractive. Thus,the desulfurization and/or denitrogenation catalyst may be any one ofthose known and used for such purposes in the prior art. Prominentcatalysts used for this purpose include cobalt molybdate on alumina withor without small amounts of silica, nickel sulfide, tungsten sulfide,and nickel-tungsten sulfide alone or on a support material such asalumina which may or may not contain small amounts of combined silica.Other suitable and known desulfurization catalysts may also be employed.

To facilitate an understanding of the described combination process,reference will now be had to FIG. 3. In the arrangement of FIG. 3, arelatively heavy hydrocarbon feed such as a residual oil containingsulfur and metal contaminants is introduced to the process through line10 to furnace 11 wherein the hydrocarbon feed is heated to an elevatedtemperature in the range of from about 650 F. to about 850 F. Thehydrocarbon feed may be heated either alone or in combination withhydrogen rich gas supplied through line 12, it being preferred to mixthe hydrogen rich gas with the feed prior to being heated in thefurnace. Thereafter,

the heated mixture is introduced through line 13 'to demetalationreactor 14. Make-up fresh catalyst may be added with the hydrocarbonfeed through line 15 or directly to the demetalation reactor. Thedemetalation reactor can be operated under liquid phase conditionswherein finely divided manganese nodules are added to and maintained insuspended motion by the liquid hydrocarbon flowing upwardly through thedemetalation reactor. The rate of flow of the liquid feed upwardlythrough the demetalation reactor in this type of operation issufficiently high to suspend the catalyst particles in a fairly randommovement. The technique of causing random movement of particulatematerial by the upward flow of the liquid has been identified with theprior art as ebullition. The demetalation of the feed may also beaccomplished in a dense fluid bed of solid particulate material, amoving bed operation, or other convenient means for effectingdemetalation where the solid particulate material can be replaced asrequired after becoming spent.

The liquid hydrocarbon leaves the upper portion of the demetalationreactor through line 20. Hydrogen gas is purged from the upper portionof the demetalation reactor through line 21. A portion of this gas maybe recycled to the demetalation reactor through line 22 provided withpump 23 and connected to line 12. Make-up hydrogen can be providedthrough line 24, also connected to line 12, if make-up hydrogen gas isrequired. At the level at which the hydrocarbon leaves the demetalationreactor, the hydrocarbon may contain catalyst fines and a finesseparator 25 is provided. The fines separator may be a cycloneseparator, filter arrangement, or any other convenient means forseparating the entrained fines from the withdrawn liquid materiaL'Liquidmaterial is withdrawn from the fines separator through line 30 providedwith pump 31 and passed on for further processing. If desired, intermediate fractionation, not shown, can be provided.

Spent fines,'having relatively high concentrations of deposited metalstherein of nickel, vanadium, copper and iron, may be withdrawn from thelower portion of the demetalation reactor through line 32.

Demetalation in the reactor will be carried out under the conditionspreviously mentioned, i.e., temperature within the range of from about650 F. to 850 F., a pressure within the range of to 3,000 psig, and aspace velocity within the range of 0.2 to about 4. Some desulfurizationof the charge will also be accomplished during demetalation but will beless effective than desired to be accomplished in the second step of theprocess.

In the second step of the process, the hydrocarbon charge recovered fromthe demetalation reactor, and in which the metals level has beensignificantly reduced, is then subjected to catalytichydrodesulfurization. For this purpose, the hydrocarbon charge is passedtofurnace 33 and thence through lines 34 and 35 to desulfurizationreactor 36. Hydrogen make-up is provided through line 40. Catalytichydrodesulfurization of sulfur-bearing hydrocarbon charge material hasbeen known and practiced in the petroleum refining art for years.Generally speaking, satisfactory desulfurization results are obtainedwhen operating at a temperature in the range of from about 650F. toabout 850 F. and a pressure in the range of about 500 to about 3,000psig when employing a space velocity in the range of about 3. Suitablecatalysts have already been described above.

In the desulfurization reactor, the desulfurization zone comprises afixed catalyst bed through which the hydrocarbon charge is passeddownwardly under desulfurizing conditions. Other types ofdesulfurization contact zones may be employed such as the trickleprocess or an ebullating bed of catalyst. In the arrangement shown, thehydrocarbon charge, in admixture with hydrogen rich gas in suitableproportions, is caused to through line 43. This gasiform stream may betreated to produce a hydrogen rich stream by any one of a number ofknown techniques and the thus produced hydrogen rich stream recycledthrough line 35 for admixture with the hydrocarbon charge to bedesulfurized. The remainder of the gasiform stream is purged from thesystem through line 45. Desulfurized product is removed from theseparator through line 46.

It is contemplated having more than one desulfurization zone in sequencein which the latter zone or zones, depending on the number employed,will be employed to effect substantial denitrogenation of the hydrogencharge when required. Thus the process contemplates a third catalyticcontact zone (not shown) for effecting more complete desulfurizationand/or denitrogenation of the hydrocarbon charge in which case the thirdzone may be placed after the separator.

Concerning processing of hydrocarbon charge stock by catalytic crackingsubsequent to demetalation, metal poisoning of the catalysts employedfor cracking can lead to severe problems such as low gas density due tothe formation of hydrogen, higher gas make, and lowered gasoline yields.This problem is generally circumvented by controlling the allowablemetals content of the feed stock to the cracking unit. However, thisrestriction also limits the percentage of crude which can providesuitable feed stock to a cracking unit.

Metals content of a catalytic cracking stock is often expressed in termsof a metals factor which is defined as parts per million (ppm) Fe 1+ ppmV 10 times the ppm Ni 10 times the ppm Cu. in general, for satisfactoryperformance of a catalytic cracking unit, the metals factor of the feedstock should be limited to about 5. The invention allows the use of aprocess complex which includes demetalation which removes, for example,90 percent of the metals, thus the metals fac- 'tor of the feed stock tothis catalytic processing complex can now be as high as 50. This in turnwill significantly increase the percentage of crude which provides anacceptable feed stock for catalytic cracking. This processingcombination is accomplished by distillation separation of a charge stockinto a lighter and a heavier metals rich portion, demetalation of theheavier portion, and feeding the demetalized effluent to the catalyticcracking unit; all or part of the lighter portion would preferably befed to the same catalytic cracking unit.

Reference will now be had to FIG. 4. The hydrocarbon charge stock, i.e.,crude oil, is brought into an. atmospheric pressure still 50 throughline 51. Light gases are removed from the still through line 52 whilethe fraction boiling between the light gases and 400 F. is removedthrough line 53. The 400-600 F. material from this still is used forcatalytic cracking and is passed through lines 54 and 55 to catalyticcracking unit 60. The bottoms from the atmospheric still are passedthrough line 61 on to a vacuum still 62. The overhead from the vacuumstill is passed through line 63 along with hydrogen to a demetalationreactor 64, while the bottoms will generally be passed through line 65to thermal processing. The effluent from the demetalation reactor isthen passed on to the catalytic cracking unit through line 55. The cuttemperature of the vacuum still depends on the specific crude oil and Ythe efficiency of the demetalation reactor, and is adjusted to yield aneffluent from the demetalation reactor having a metals factor nogreaterthan about 5. When the demetalation reactor is efficient enough, thevacuum tower can be completely circumvented and the bottoms from theatmospheric still passed directly to a the demetalation unit.

from the atmospheric still Both the conversion and gasoline yield fromcatalytic cracking can often be improved by prior hydrogenation of thefeed stock. Either the percentage of crude suitable as feed stock tosuch a conventional process or the life of the relatively expensivehydrogenation catalyst can be increased by providing a priordemetalation process using a relatively cheap disposable catalyst.Thus,'the demetalation reactor 64 of FIG. 4 could be replaced by acomplex consisting of both a demetalation reactor and a hydrogenationreactor (not shown). For example, the system of demetalation plusdesulfurization and/or denitrogenation, described in more detail in FIG.3, could be used. The demetalation reactor now permits an increase inthe cut temperature of the vacuum still or possibly direct use of thebottoms with an increase in the amount of catalytic cracking feed stock.The hydrogenation reactor, in turn, increases the hydrogen content ofthe feed stock leading to greater gasoline production from a givenamount of feed stock. In the absence of the demetalation reactor, eitherincreasing the cut temperature or completely bypassing the vacuum stillwould increase the amount of metals reaching the hydrogenation catalystand would significantly curtail the life of this more expensivecatalyst.

The following examples will be illustrative of the invention.

EXAMPLE 1 This example will illustrate the catalytic effect of manganesenodules on demetalation of a topped crude charge stock. The charge stockwas Agha .lari topped The manganese nodules were obtained from thebottom of Sturgeon Bay in Lake Michigan. These nodules, after recoveryfrom the lake bottom, were washed to remove salt, water, and mud. Theywere then crushed, leached with boiling water five times, dried toconstant weight at C., and sieved to 14-30 mesh (U.S. Standard SieveSeries). The nodules had the following physical characteristics andchemical composition:

Surface area, square meters per gram (mg 200 Particle density, grams percubic centimeter (g cm" 1.49 Pore diameter, Angstrom units (A) 81 Porevolume, cubic centimeters per gram (cmg'A 1) 0.409 Real density, g cm'3.75 Manganese (Mn), wt. 9.19 Iron (Fe), wt. 35.4 Nickel (Ni), wt. 0.01Cobaltous oxide (C00), wt. 0.04 Molybdenum trioxide (M003), Wt. 0.08

The nodules were placed in a downflow trickle-bed reactor, and hydrogenand the topped crude were passed through the reactor for 7 days. Thereaction conditions and results are shown in Table I.

The hydrogen consumption in Table 1, and in the subsequent tables, was atime-weighted average consumption over the course of the run.

TABLE I Temperature 750F. Pressure 2,000 psig Liquid Hourly SpaceVelocity (LHSV)- 1.19 Volumes of Charge Stock per Volume of ManganeseNodules Hydrogen Circulation (H, Circ.) 10240-10880 Standard Cubic Feetof Hydrogen per Barrel of Charge Stock (SCF/B) TIME ON STREAM, DAYSHYDROGEN CONSUMPTION, Standard Cubic Feet of Hydrogen per Barrel ofCharge Stock (SCF/B) 73 FLUID PRODUCT PROPERTIES It will be observedfrom the table that the demetalation varied from 98.8 to 68.9 percentover the course of the 7-day run.

EXAMPLE 2 In this example, the effect of sulfiding the manganese nodulesis demonstrated. The charge stock and the nodules were the same as thoseused in Example 1. However, after loading the nodules into the reactor,the nodules were sulfided by passing through the reactor 100 percenthydrogen sulfide at 320 F., at' 1 atmosphere pressure, and at a spacevelocity of 480 volumes of hydrogen sulfide per volume of nodules for aperiod of 8 hours. The topped crude oil and hydrogen were passed throughthe reactor for a period of 10 days. Reaction conditions and results aregiven in Table II.

It will be seen, comparing Tables I and 11, that sulfiding of thecatalyst resulted in improvements in desulfurization, CCR reduction, anddemetalation although the improvements in demetalation did not becomemarked until after two days on stream. The beneficial effects were mostpronounced on the CCR reduction and least pronounced on thedemetalation. It will also be seen that the hydrogen consumption was 103SCF/B whereas in Example 1 the hydrogen consumption was 73 SCF/B. Thehigher consumption of hydrogen in Example 2 is not considered to be ofsignificance in view of the fact that hydrogen consumption data issensitive to small errors in analysis. Any differences in hydrogenconsumption of less than 50 SCF/B can usually be attributed to analysiserror.

TABLE 11 Temperature 750 F.

Pressure 2000 psig H, Circ 9,640-10,560 SCF/B TIME ON STREAM, DAYS 0.060.2 1.0 1.2 2.1 3.3 4.1 7.1 8.1 9.1 10.1 HYDROGEN CONSUMPTION,SCF/l3-103 LIQUID PRODUCT PROPERTIES Gravity, AP1

26.0 215.026.) 26.2 25.7 25.7 25.5 25.5 25.4 25.3 25.0 Sulfur,wt%

0.70 1.101.42 1.431.48 1.541.58 1.691.67 1.70 1.65 Nitrogen, wt

0.140.18 0.18 0.18 0.19 0.19 0.19 0.19 0.19 0.09 CCR.wt%

' 2.613.40 3.57 3.15 3.34 3.73 3.63 3.59 3.58 Ni,ppm

0.34 0.812.6 2.8 3.5 4.3 4.0 4.8 5.9 5.4 4.7 V, ppm

0.31 0.82 3.5 3.9 5.1 6.4 6.3 8.2 8.5 9.2 9.6 DESULFURIZATION 68.250.0355 35.0 32.7 30.0 28.2 23.2 24.1 22.7 25.0 CCR REDUCTION 41.123.319.4 38.9 24.6158 18.1 19.0 19.2 %DEMETALATION EXAMPLES This examplewill illustrate the effect of temperature on the demetalation activityof sulfided manganese nodules.

The procedure set forth above in Example 2 was continued for anadditional period of 6.9 days. However, during this additional period,the temperatures employed were 800 and 850 F. The reaction conditionsand results are given in Table III. In Table III, the hydrogenconsumption is given only for the period that the reaction was carriedout at 800 F. During the period at which the reaction was carried out at850 F difficulty was encountered in obtaining measurement of hydrogenconsumption.

It will be noted from Tables 11 and III that, at 750 F., thedemetalation at the beginning of operation was 98.9 percent. However,demetalation decreased as the operation continued and at the end of 10days had declined to .8 percent. On the other hand, with the temperaturebeing increased at this time to 800 F., demetalation rose to 96.4percent and remained at this figure or higher for the entire 800 F.portion of the operation. At 850 F., the demetalation was over 99percent complete.

TABLE 111 Pressure-2000 psig LHSV-1.27 11. Circ-9,830-10,560 SCF/B masonSTREAMQDAYS 11.1 14.4 14.9 15.4 15.9 16.6 16.9 TEMPERATURE. F. 1200 11001100 soo 1100 1150 s50 HYDROGEN CONSUMP- TION. SCF/B-166 LIQUID PRODUCTPROPERTIES Gravity. API 25.9 26.9 26.7 26.7 26.8 30.5 30.5 su1rur.w1%1.29 1.37 1.39 1.32 1.41 0.11s 0.89 N1trogen.wt% 0.10 0.16 0.111 0.1110.111 0.15 0.17 CCR.wt% 2.87 3.05 3.14 5.20 3.11 1.15 1.16 N1.ppm 1.11.2 1.4 1.3 1.3 0.2 0.2 v.11pm 1.0 0.7- 0.7 0.7 0.6 0.1 0.3

96DESULFURIZATION 41.4 37.7 36.8 37.3 35.9 60.0 59.5

.%CCR REDUCTION 35.2 31.2 29.1 27.8 29.8 74.0 73.4

%DEMETALA TION 96.4 96.8 96.4 96.6 96.8 99.5 99.2

EXAMPLE4 This'example will illustrate the catalytic effect of themanganese nodules for demetalation of a whole crude oil. The crude oilwas Kuwait whole crude and had the following physical properties andchemical composition:

Gravity, API 31.1

mm10 n 4 P% M v .mmm .H Inr P mmm m II I. lull mGMNCNV a m e o em s ll930740 0 2 99 w 2050 2 fl r c e m. m s m e m w t y W 6 h WT s I Mwl u mu p n em %m S X L ME WDL a nm mrmrm m muflmm w AwMCHN mw y mm T Pdownflow trick|e bed reactor and lfid d by passing Reaction conditionsand results are given in Table V. 1 100 percent hydrogen lfid throughthem at 45 F. It Will be seen from Table V that demetalation vaned and 1atmosphere pressure for 8 hours at a space between and P velocity of 480volumes per volume of nodules per 10 TABLEV hour. After sulfiding, thecrude oil and hydrogen were passed through the reactor. The reactionconditions Temperature-800 F. and results are given in Table IV. ffigv i88 PM it will be seen that the demetalation activity of the 11,011613,000 SCF/B catalyst was high throughout the period of the reaction. ONSTREAM DAYS 0 2 o 6 Demetalation was 96.9'percent after 2 hours ofopera- HYDROGEN CONSUMPTION h 283 LIOUlD PRODUCT PROPERTIES Gravity, APIguli'ur, wt itro en. wt CCRPwtib PP DESULFURIZATION CCR REDUCTIONDEMETALATION tion. Even after 3 days of operation, demetalation wasstill 82 percent.

EXAMPLE 6 v This example will illustrate the catalytic effect ofmanganese nodules on the demetalation of petroleum res1dual oil. Thepetroleum res1dual oil was a Kuwait atmospheric residual oil and had thefollowing characteristics:

TABLE IV Temperature 750 F.

LHSV 1.33

Pressue 2000 psig H, Circ 6,9l0-9,870 SCF/B TIME ON STREAM, HOU2RS 13HYDROGEN CONSUMPTION, SCF/B 52 LlQUlD PRODUCT PROPERTIES Gravity, API303 30.8 30.8 30.7 30.6 30.4 30.4 30.1 Sulfur, wt 1.00 1.82 2.01 1.992.04 2.10 2.16 2.18 Nitrogen, wt% 0.06 0.11 QJZJLIZ 11-13 0-13 11.

Ni, ppm PP DE Gravity, API Sulfur, wt. Nitrogen, wt. CCR, wt. I I

' 40 I The nodules were the same as those employed in Example 1 exceptthat they were sieved to 10-20 mesh and were sulfided. Sulfiding waseffected by loading the nodules into an upflow reactor and passinghydrogen the same'conditions as set forth in Example 2. Reactionconditions and results are given in Table VI.

it will be noted that, over the approximately 19-day run, thedemetalation varied between 83.6 and 95.5 percent.

TABLE VI lTemperature, 800 F.; LHSV, 1.0; pressure, 2,000 p.s.i.g.]

EXAMPLE 5 This example will illustrate the catalytic effect of manganesenodules for demetalation of another topped 222..-. Liquid productproperties:

111 SULFURlZATlON CCR REDUCTION DEMETALATION crude oil. The nodules werethe same as those em- 45 sulfide through them. Sulfiding was carried outunder ployed in Example 1 except that they were sieved to 10-20 mesh.The nodules were packed into a downflow trickle-bed reactor and sulfidedas described in Example 1. The charge stock was a Kuwait topped crudeand had the following characteristics:

Time on stream, days....-.... Hydrogen consumption, s.e.!./b.-

as ame Ma unm n wsman 6999 1 innem Gravity, API- Sulfur, weight,percent........ Nitrogen, weight percent...... OCR, weight percent.

Percent demetalatlon Time on stream, days. Hydrogen Liq 82 ame 0 0 L mm0 4 .54 22 wwm a2 ame 88 5 AME H ulfurlzation gen, weig CCR, weightpercent Nitro D- Percent 11 Percent CC R reduction. Percentdemetalation.

EXAMPLE 7 This example will illustrate the results obtained employing aconventional catalyst for demetalation of the same residual oil employedin Example 6. The catalyst employed was a molybdenum oxide-aluminumoxide catalyst and comprised 11.1 weight percent of M00,

on A1 It is identified by the trade name I-larshaw v Mo 1210 T. Thiscatalyst was placed in a downflow reactor and the residual oil andhydrogen were passed through it at a variety of conditions. Theconditions and results are given in Table VII. The conditions usedbetween 4.79 and 9.42 days in this table were essentially the same asthose employed in Example 6.

As shown in Table VII, the demetalation varied between 82.2 and 95.0percent. This is comparable to the extent of demetalation obtained withthe manganese nodules in Example 6. However, the hydrogen consumption inExample 7 was 563 SCF/B as compared to the lower hydrogen consumption inExample 6 of 222 SCF/B.

TABLE vrr [Temperature, 800 F.; LHSV, 1.0; pressure, 2,000 p.s.1.g.]

for a period of 3 days at 2,000 psig at 700-7 50 F. and I a spacevelocity of 1.16 volumes of gas oil per volume of nodules per hour.Thereafter, the West Texas Sour vacuum residual oil was passed over thenodules along with the hydrogen at a temperature of 750 F. After ashorttime at 750 F., the temperature was raised to 800 F. Resultsobtained at 800 F. are given in Table VIII.

The three other catalysts were, respectively, (I) an Time on Stream,days 4.79 4.83 4.87 5.25 5.07 5.79 6.25

liggarogen consumption, so! lb Liquid product properties Gravlty,API24.2 24.2 24.4 24.4 Sulfur, welg ht percent ..1.83 1.77 1.86 1.58 1.601.57 1.43 1353B, welg percent 4. 62 4.08

EXAMPLE 8 Gravity, API 7.3 Hydrogen, wt. 10.05 Sulfur, wt. 4.02Nitrogen, wt. 0.36 CCR, wt. 15.9 Ni, ppm 19 V, ppm 32 The manganesenodules were obtained from the Blake Plateau in the Atlantic Ocean and,after crushing and washing with hot water, had the following physicalproperties and chemical composition:

Surface Area, mg'

Particle Density, g cm' 1.21 Pore Diameter, A 103 Pore Volume, (cmg 0.58Real density, g cm' 4.06 Mn, wt. 20.9 Fe, wt. 13.3 Nhwnfi 0.92 CoO. wt.0.43 M00 wt. 0.1

These nodules were sieved to 14-30 mesh and were loaded into an upflowreactor, and a West Texas Sour vacuum gas oil which was relatively freeof metallic constituents was passed over them along with hydrogen TABLEVIII CATALYST Nodules 1 II 111 TIME ON STREAM, DAYS 3.6 6.9 5.6TEMPERATURE, F. v 803 804 801 800 PRESSURE, P816 2000 2000 2000 2000LHSV 0.97 0.83 0.74 0.89 H, CIRC 6620 8050 9560 7840 HYDROGENCONSUMPTION, SCF/B 235 345 490 1060 LlQUlD PRODUCT PROPERTIES Gravity,API 11.2 11.8 12.8 17.7 Hydrogen, wt. 10.38 10.37 10.36 11.45 Sulfur,wt. k 2.93 3.46 2.91 0.62 Nitrogen, wt. 1: 0.38 0.37 0.36 0.29 CCR, wt.11.9 14.0 8.1 Nickel, ppm 10 19 12 3 Vanadium, Em 13.5 27 10 0.8 DEMETAATION v Total time on stream counting 3 days with vacuum gas oil.

The table indicates that the extent of demetalation employing thenodules was 53.9 percent. However, it wasconsidered that this was not arepresentative figure since, on opening the reactor, it was discoveredthat about half of the catalyst charge had been removed from the reactorby the oil and hydrogen passed through it. The table also indicates thatthe extent of demetalation employing Catalyst III was 92.5 percent.However, the table also indicates that, while the nodules took out overone-half the metal removed by Catalyst III, the hydrogen consumptionwith the nodules was less than one-fourth that of Catalyst [11. Further,the table shows that the nodules are far superior to Catalyst I whichcontains no metal or metal oxide component generally considered to havehydrogenation activity and comparable to Catalyst 11. The table alsoshows that the hydrogen consumption with the nodules is significantlyless than Catalyst 1 and less than one-half that of Catalyst 11.

EXAMPLE 9 This example will illustrate the demetalation of a toppedpetroleum crude oil at relatively low pressures of hydrogen. Arelatively high space velocity also was employed.

The manganese nodules were the same as those employed in Example 2 andthe topped petroleumcrude oil was the same as that employed inExample 1. The reaction conditions and the results obtained are given inTable 1X.

As shown in the table, the percent demetalation varied between 43.7 and78.3 percent over the course of the run.

TABLE 1X Temperature 750 F.

Pressure 1015 psig LHSV 2.9

H Circ 10,000 SCF/B TIME ON STREAM, DAYS This example will illustratethe demetalation of a topped petroleum crude oil at a lower pressure andat a lower space velocity than in the previous example.

The manganese nodules and the topped petroleum crude oil were the sameas those in the previous example. During the run, the temperature wasincreased from 750 F. to 800 F. The reaction conditions and the resultsobtained are shown in Table X.

- As shown, the percent demetalation varied between 93.1 and 59.2percent over the course of the run.

TABLE X Temperature 750-800 F.

Pressure 560 psig LHSV 1.1

H, Circ 10,000 SCF/B TIME ON STREAM, DAYS 0.110.25 0.641.14 1.64 2.142.63 3.09 HYDROGEN CONSUMPTION, SCFIB 85 TEMPERATURE, F.

750 750 750 750 750 800 800 800 LlQUlD PRODUCT PROPERTIES Gravity, All27.5 25.5 25.6 25.3 25.4 26.4 Su1fur,wt% 1.04 1.511.63 1.651.45 1.531.54 .Nitrogen,wt% .15 0.19 0.19 0190.18 0.19 0.19 CCR,wt% 2.38 3.123.90 4.17 4.27 3.33 3.63 3.54 Ni,ppm 1.4 2.8 5.5 7.1 7.6 4.6 5.6 5.7 V,pm 2.7 6.0 l1.816.9 16.5 7.9 8.6 7.8 DESULFURIZATION 52.7 31.4 25.9 25.034.1 30.5 30.0 CCR REDUCTION 46.3 29.6 12.0 5.9 3.6 24.8 18.1 20.0DEMETALATlON EXAMPLE 11 This example will illustrate the demetalationactivity of manganese nodules obtained from the Atlantic Ocean on atopped petroleum crude oil.

The nodules employed were obtained from the Blake Plateau in theAtlantic Ocean. These nodules, after crushing and washing with hotwater, had the following physical properties and chemical composition:

Surface Area, mg' 226 Particle Density, g cm 1.43 Pore Diameter, A 73Pore Volume, em 3" 0.41 Real Density, g cm" 3.53 Mn, wt. 18.8 Fe, wt.11: 12.3 Ni, wt. 0.72 C9911! M003, W1. I 0.1

The topped petroleum crude oil was the same as that employed inExample 1. The reaction conditions an results obtained are given inTable X1.

As shown, the demetalation varied between 95.8 and 79.7 percent over thecourse of the run.

TABLE Xl I Temperature 750 F. Pressure 2000 psig- LHSV 1.3 H, Circ10,000 SCF/B TlME ON STREAM, DAYS .10 0.45 0.90 1.36 HYDROGENCONSUMPTION, SCF/B 174 LIQUID PRODUCT PROPERTIES Gravity, AP1 25.5 24.7H. 25.3 Sulfur, wt 1.40 1.63 L 1.69 Nitrogen, wt 0.17 .19 .20 20 CCR,wt%3.19 3.85 3.89 3.89 Ni, ppm 1.2 2.7 4.9 5.9 V, m 1.3 5.0 7.1 5.9SESULFURIZATION 6.4 25.9 22.3 23.2 CCR REDUCTION 28.0 13.1 12.2 12.1DEMETALATION EXAMPLE 12 Surface Area, mg"

230 Particle Density, g cm' 1.52 Pore Diameter, A 69 Pore Volume, cm g0.40 Real Density, g cm' 3.80 Mn, wt. 28.5 Fe, wt. 13.9 Ni, wt. 1.21990.16% 2 M00 wt. 0.1

The nodules were sieved to 14-30 mesh and sulfided in accordance withthe procedure described in Example 2. The reaction conditions andresults obtained are given in Table X11.

As shown, the demetalation varied between 60.1 and 86.1 percent over thecourse of the run.

19 TABLE x11 Temperature 750 F. Pressure 2000 psig 1.11sv- 1.2 H, can10,000 SCF/B TIME ON STREAM, DAYS 0.06 0.20 0.60 1.101.60 2.15 2.60HYDROGEN CONSUMPTION, SCF/B 69 LIQUID PRODUCT PROPERTIES Gravity, APl26.5 25.5 25.1 25.0 25.0 25.0 25.0 Sulfur,wt% 1.20 1.391.49 1.501.521.47 1.33 Nitrogen, was .17 .19 .20 .20 .20 .20 .20 ccn, W193 3.17 3.534,044.29. 4.23 4.11 4.15 Ni,ppm 4.1 3.2 5.1 8.9 6.9 6.9 7.8 v.ppm 1.45.0 8.2 14.7134 9.3 14.3 DESULFURIZATION 45.5 36.8 32.3 31.8 30.9 33.230.5 CRR REDUCTION 28.4 19.2 8.8 3.2 4.5 7.2 6.3 DEMETALATION EXAMPLE l3This example will demonstrate the sensitivity of manganese nodules tothe effect of sulfur with respect to the hydrogenation of aromaticcompounds.

In this example, in the first portion thereof, benzene and hydrogen werepassed over three different catalysts packed into a reactor. The firsttwo catalysts were Atlantic Ocean nodules having the physicalcharacteristics and chemical composition as given in Example 8, and LakeMichigan nodules having the physical properties and chemical compositiongiven in Example 1. The third catalyst was the same type of conventionalcatalyst containing CoO/MoO employed in Example 7. The reactionconditions were as follows:

Temperature 700 F. Pressure 1,050 psig LHSV 4.0 Ratio of Hydrogen toBenzene 2.68

At the end of two hours, the effluent stream from the reactors wasanalyzed for the proportion of cyclohexane contained therein. Theresults are given in Table XIII.

TABLE Xlll Catalyst Mole Percent of C clohexane Atlantic Ocean Nodules87 La lgej ijghjgan Nodules 45.3 CoO/MoO3 93.1

It will be observed from Table XIII that each of the catalysts hadsignificant benzene hydrogenation activity, with the Coo/M having thegreatest activity.

In the second portion of this example, the procedure was repeated exceptthat an olefin, i.e., hexene-l, and a sulfur-containing organiccompound, i.e., Z-methyl thiophene, were mixed with the benzene. Themixture had the following composition in weight percent Benzene 79.4Hexene-l l8.2 Z-Methyl Thiophene 2.4

The reaction conditions were:

Temperature 700 F. Pressure 1050 psig Ll-lSV 4.0 Ratio of Hydrogen toother reactants 10.0

After 22.5 hours on stream, the effluent streams from the reactors wereanalyzed to determine the extent of benzene and hexene-l hydrogenationand sulfur removal. The results are given in Table XIV.

TABLE XIV Benzene Hexene-l Sulfur yd o- Hydro- Removal genated genatedWeight Mole Mole Percent Percent Percent Catalyst Atlantic Ocean NodulesLake Michigan u es. COO/M003 The runs were continued for an additional 5hours but the temperature was increased to 800 F. Analyses were againmade of the effluent stream from the reactors and the results are givenin Table XV.

TABLE XV Benzene Hexene-l Sulfur Hydro Hydro- Removal genated genatedMole Mole Percent Percent 93 Catalyst Percent Atlantic Ocean 0.l 92Nodules Lake Michigan Nodules coo/H065 pound.

EXAMPLE 14 This example will illustrate the processing sequence,described in connection with FIG. 3, of demetalation followed byhydroprocessing for sulfur and nitrogen removal. The Kuwait atmosphericresidual oil described in Example 6 is fed to the demetalation reactor14. The catalyst in the demetalation reactor is manganese nodules whichhave been crushed to small particle size. The ebullating beddemetalation reactor is operated at 800 F., a Ll-ISV of 1.0, a pressureof 2,000 psig, and a hydrogen circulation rate of 10,000 SCF/B. Tenpercent of the catalyst in the demetalation reactor is withdrawn dailyand an equivalent amount of fresh catalyst added daily.

The metals content of the liquid product from the demetalation reactoris significantly reduced relative to that of the feed to thedemetalation reactor. The sulfur content is also reduced but to a lesserextent. The product from the demetalation reactor is passed on to thedesulfurization reactor 36. The catalyst in the desulfurization reactoris cobalt molybdate on alumina. The desulfurization reactor is operatedat a LI-ISV of 1.0, a temperature of 800 F., a pressure of 2,000 psigand a hydrogen circulation rate of 10,000 SCF/B. The sulfur content ofthe product from the desulfurization reactor is significantly reducedrelative to the feed to the desulfurization reactor.

EXAMPLE 15 This example will illustrate the processing sequence,described above in connection with FIG. 4, of demetalation prior tocatalytic cracking. A Kuwait crude oil is fed to atmospheric still 50.The bottoms from the atmospheric still, which are very similar to theKuwait atmospheric residual oil described in Example Weight 6, arepassed to vacuum still 62. The cut temperature of the vacuum still isadjusted so that the overhead has a metals factor of about 50. Thisoverhead is then passed on to demetalation reactor 64. The catalyst inthe demetalation reactor is manganese nodules which have been crushed tosmall particle size. The ebullating bed demetalation reactor is operatedat a LHSV of 0.5, a pressure of 2,000 psig, and a hydrogen circulationrate of 10,000 SCF/B. Ten percent of the catalyst in the demetalationreactor is withdrawn daily" and an equivalent amount of fresh catalystadded daily. The temperature of the demetalation reactor is controlledsuch that the product from this reactor has a metals factor of about 5.This product is then passed on to catalytic cracking unit 60.

EXAMPLE 16 This example will illustrate a processing sequence ofdemetalation and hydrogenation prior to catalytic cracking. A Kuwaitcrude oil is fed to atmospheric still 50 as illustrated in FIG. 4. Thebottoms from the atmospheric still, which are very similar to the Kuwaitatmospheric residual oil described in Example 6, are passed to vacuumstill 62. The cut temperature of the vacuum still is adjusted so thatthe overhead has a metals factor of about 50. This overhead is thenpassed on to demetalation reactor 64 containing manganese nodules whichhave been crushed to small particle size. The ebullating beddemetalation reactor is operated at a temperature of 800 F., a Ll-lSV of1.0, a pressure of 2,000 psig, and a hydrogen circulation rate of 10,000SCF/B. Ten percent of the catalyst in the demetalation reactor iswithdrawn daily and an equivalent of fresh catalyst added daily.

The product from the demetalation reactor, which has been significantlyreduced in metals content relative to the feed to the demetalationreactor, is passed on to a hydrogenation reactor, i.e., thedesulfurization reactor 36 illustrated in FIG. 3. The catalyst in thehydrogenation reactor is cobalt molybdate on alumina. The hydrogenationreactor is operated at a LHSV of 1.0, a temperature of 700 F., apressure of 2,000 psig, and a hydrogen circulation rate of 7,500 SCF/B.The hydrogen content of the liquid effluent from the hydrogenationreactor is significantly increased relative to the feed to thehydrogenation reactor. This effluent is then passed on to the catalyticcracking unit 60.

The gasoline yield and conversion from this processing sequence are nowfar in excess of that obtainable by catalytic cracking alone; and asteady-state cracking operation is achieved with a charge stock metalsinput far in excess of that achieved by catalytic cracking.

We claim:

1. A process for the demetalation of a hydrocarbon charge stockcontaining metal impurities comprising contacting said hydrocarboncharge stock with hydrogen and with a catalyst comprising thenaturallyoccurring, underwater deposit known as manganese 3. The processof claim 2 wherein said at least a porfrom said manganese nodule byleaching said manganese nodule with an aqueous solution of acid.

4. The process of claim 2 wherein said at least a portion of itsmolybdenum content has been removed from said manganese nodule byleaching said manganese nodule with an aqueous solution of a base.

5. The process of claim 4 wherein said aqueous solution of a base has apH of at least 8.

6. The process of claim 4 wherein said aqueous solution of a base has apH of at least 10.

7. The process of claim 1 wherein said catalyst is obtained bycontacting said manganese nodules with hydrogen sulfide.

8. The process of claim 7 wherein said manganese nodules are contactedwith said hydrogen sulfide at a temperature from about 300 F. to about450 F.

9. The process of claim 7 wherein said manganese nodules are contactedwith said hydrogen sulfide for a time from about 4 hours to about 8hours.

10. The process of claim 7 wherein said manganese nodules are contactedwith said hydrogen sulfide at a and said hydrogen are contacted withsaid catalyst at a.

pressure from about to about 3,000 pounds per square inch gage.

14. The process of claim 1 wherein said charge stock and said hydrogenare contacted with said catalyst at a pressure of 500-2,000 pounds persquare inch gage.

15. The process of claim 1 wherein said charge stock and said hydrogenare contacted with said catalyst at a temperature from about 650 F. toabout 850 F. and at a pressure from about 100 to about 1,000 pounds persquare inch gage.

16. The process of claim 1 wherein said charge stock and said hydrogenare contacted with said catalyst by passing said charge stock through abed of said catalyst.

17. The process of claim 16 wherein said charge 'stock is passed throughsaid bed of catalyst at a rate from about 0.2 to about 4 volumes ofcharge stock per volume of catalystper hour. I

18. The process of claim 16 wherein said charge stock is passed throughsaid bed of material at a rate from about 0.5 to about 2 volumes ofcharge stock per volume of material per hour.

19. The process of claim 16 wherein the circulation rate of saidhydrogen is 2,000-15,000 standard cubic feet of hydrogen per barrel ofcharge stock.

20. The process of claim 16 wherein the circulation rate of saidhydrogen is 5,000-10,000 standard cubic feet of hydrogen per barrel ofcharge stock.

21. The process of claim 16 wherein said charge stock is passed throughsaid bed of catalyst at a rate from about 0.2 to about 4 volumes ofcharge stock per volume of catalyst per hour and the circulation rate ofsaid hydrogen is 2,000-15,000 standard cubic feet of hydrogen per barrelof charge stock.

23. A process which comprises demetalizing a hydrocarbon charge stockcontaining metal impurities by contacting said hydrocarbon charge stockwith hydrogen and with a catalyst comprising the naturallyoccurring,underwater deposit known as manganese nodules and desulfurizing thedemetallized hydrocarbon charge stock by contacting said demetallizedhydrocarbon charge stock with hydrogen and with a desulfurizing catalystunder hydrodesulfurizing conditions.

1. A process for the demetalation of a hydrocarbon charge stockcontaining metal impurities comprising contacting said hydrocarboncharge stock with hydrogen and with a catalyst comprising thenaturally-occurring, underwater deposit known as manganese nodules. 2.The process of claim 1 wherein said catalyst is a manganese nodule whichcontains copper, nickel or molybdenum in its composition and which hashad at least a portion of its copper, nickel or molybdenum contentremoved therefrom.
 3. The process of claim 2 wherein said at least aportion of its copper or nickel content has been removed from saidmanganese nodule by leaching said manganese nodule with an aqueoussolution of acid.
 4. The process of claim 2 wherein said at least aportion of its molybdenum content has been removed from said manganesenodule by leaching said manganese nodule with an aqueous solution of abase.
 5. The process of claim 4 wherein said aqueous solution of a basehas a pH of at least
 8. 6. The process of claim 4 wherein said aqueoussolution of a base has a pH of at least
 10. 7. The process of claim 1wherein said catalyst is obtained by contacting said manganese noduleswith hydrogen sulfide.
 8. The process of claim 7 wherein said manganesenodules are contacted with said hydrogen sulfide at a temperature fromabout 300* F. to about 450* F.
 9. The process of claim 7 wherein saidmanganese nodules are contacted with said hydrogen sulfide for a timefrom about 4 hours to about 8 hours.
 10. The process of claim 7 whereinsaid manganese nodules are contacted with said hydrogen sulfide at atemperature from about 300* F. to about 450* F. and for a time fromabout 4 hours to about 8 hours.
 11. The process of claim 1 wherein saidcharge stock and said hydrogen are contacted with said catalyst at atemperature from about 650* F. to about 850* F.
 12. The process of claim1 wherein said charge stock and said hydrogen are contacted with saidcatalyst at a temperature of 750*-850* F.
 13. The process of claim 1wherein said charge stock and said hydrogen are contacted with saidcatalyst at a pressure from about 100 to about 3,000 pounds per squareinch gage.
 14. The process of claim 1 wherein said charge stock and saidhydrogen are contacted with said catalyst at a pressure of 500-2, 000pounds per square inch gage.
 15. The process of claim 1 wherein saidcharge stock and said hydrogen are contacted with said catalyst at atemperature from about 650* F. to about 850* F. and at a pressure fromabout 100 to about 1,000 pounds per square inch gage.
 16. The process ofclaim 1 wherein said charge stock and said hydrogen are contacted withsaid catalyst by passing said charge stock through a bed of saidcatalyst.
 17. The process of claim 16 wherein said charge stock ispassed through said bed of catalyst at a rate from about 0.2 to about 4volumes of charge stock per volume of catalyst per hour.
 18. The processof claim 16 wherein said charge stock is passed through said bed ofmaterial at a rate from about 0.5 to about 2 volumes of charge stock pervolume of material per hour.
 19. The process of claim 16 wherein thecirculation rate of said hydrogen is 2,000-15,000 standard cubic feet ofhydrogen per barrel of charge stock.
 20. The process of claim 16 whereinthe circulation rate of said hydrogen is 5,000-10,000 standard cubicfeet of hydrogen per barrel of charge stock.
 21. The process of claim 16wherein said charge stock is passed through said bed of catalyst at arate from About 0.2 to about 4 volumes of charge stock per volume ofcatalyst per hour and the circulation rate of said hydrogen is2,000-15,000 standard cubic feet of hydrogen per barrel of charge stock.22. A process for the demetalation of a hydrocarbon charge stockcontaining metal impurities comprising contacting said hydrocarboncharge stock with hydrogen at a temperature from about 650* F. to about850* F. and at a pressure from about 100 to about 3,000 pounds persquare inch gage and with a catalyst comprising a manganese nodule whichhas been previously contacted with hydrogen sulfide at a temperaturefrom about 300* F. to about 450* F. and for a time from about 4 hours toabout 8 hours.